Re: [Qemu-devel] [Qemu-ppc] [PULL 04/12] ppc: tlbie, tlbia and tlbisync are HV only

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 01/06/16 03:15, David Gibson wrote:

> On Tue, May 31, 2016 at 11:28:49PM +0100, Mark Cave-Ayland wrote:
>> On 31/05/16 01:41, David Gibson wrote:
>>
>>> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>>
>>> Not that anything remotely recent supports tlbia but ...
>>>
>>> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
>>> ---
>>>  target-ppc/translate.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
>>> index dfd3010..690ffd2 100644
>>> --- a/target-ppc/translate.c
>>> +++ b/target-ppc/translate.c
>>> @@ -4858,7 +4858,7 @@ static void gen_tlbie(DisasContext *ctx)
>>>  #if defined(CONFIG_USER_ONLY)
>>>      gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>  #else
>>> -    if (unlikely(ctx->pr)) {
>>> +    if (unlikely(ctx->pr || !ctx->hv)) {
>>>          gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>          return;
>>>      }
>>> @@ -4879,7 +4879,7 @@ static void gen_tlbsync(DisasContext *ctx)
>>>  #if defined(CONFIG_USER_ONLY)
>>>      gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>  #else
>>> -    if (unlikely(ctx->pr)) {
>>> +    if (unlikely(ctx->pr || !ctx->hv)) {
>>>          gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>          return;
>>>      }
>>> @@ -4898,7 +4898,7 @@ static void gen_slbia(DisasContext *ctx)
>>>  #if defined(CONFIG_USER_ONLY)
>>>      gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>  #else
>>> -    if (unlikely(ctx->pr)) {
>>> +    if (unlikely(ctx->pr || !ctx->hv)) {
>>>          gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
>>>          return;
>>>      }
>>
>> Unfortunately this patch breaks qemu-system-ppc for both g3beige and
>> mac99 under TCG causing a freeze in OpenBIOS when starting
>> qemu-system-ppc with no parameters.
> 
> Bother, sorry.
> 
> I think this is because I applied this without the patch that treats
> machines with no hypervisor mode (e.g. Apples) as always being in
> hypervisor mode.

No problem, I can cope for a couple of days or so.

>> Note that there is also another regression that has recently landed in
>> git master so you'll also need to revert
>> e7c9136977cb99c6eb52c9139f7b8d8b5fa87db9 in order to get back to a
>> functioning OpenBIOS.
> 
> I'd preter to see it fixed rather than just reverted..

Looks like the original author has found the bug, so there should be a
fix coming up for this soon (I only included it here in case you needed
an explicit test case).


ATB,

Mark.